Hi again Yann,

Here's one more link to a pdf file at Atmel's web site. This is a design refernece document for an AT89C51SND1 bases MP3 player. You might find it interesting and helpful.

http://www.atmel.com/dyn/resou...oc4207.pdf

For the record, Bert Sesam is quite correct. Unless your doing this for your own edification, or you plan to sell a hoarde of them, well, you can read what he wrote.

Good Luck.